Liquid fuel combustion apparatus



Sept. 15, 1942. -r. a. FOCKE ETAL I LIQUID FUEL COMBUSTION APPARATUS 4Sheets-Sheet 2 Filed July 14, 1939 m Mm o a 4 mum m. 4 m y mi A a we BK1 .1 E2. 1 2 3 W 1 E Q NH I a w? 5 mm. 6 0 Z 1 O 7 J 2 W \U H o .f H u vV W. m .n. g. VIM g m -1- ,9 v m MW w m m E 7%, F :11 w o 1| muuuli 0 a1 w w y 1 a I. 1 0 3 0 :55. 1 I. 5 B 2 5 a 1 2 5 1 Q g Sept. 15, 1942.T. B. FOCKE m-AL LIQUID FUEL COMBUSTION APBARATUS Filed July 14, 1939 4Sheets-Sheet 3 INVENTORJ. a FOCKE R. KIRKPATRlCK M. M ATTORNEYS.

THEODORE JOSE PH '2 t. e m s 5 Mme m n. cA

R OP n A E A MR9 .2 Y.

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9 K BN1 mm E2 E 2 Km mm .v mm M, 2. ll a B Tu W1 T A Sept. 15, 1942.

Patented Sept. 15, 1942 LIQUID FUEL COMBUSTION APPARATUS Theodore B.

Focke, Cleveland Heights, and

Joseph R. Kirkpatrick, South Euclid, Ohio, as-

signors to land, Ohio,

Perfection Stove Company, Clevea corporation of Ohio Application July14-, 1939, Serial No. 284,544

14 Claims.

This invention relates, generally, to liquid fuel combustion apparatus,and more particularly to liquid fuel burners of the bowl or pot typethat are used extensively in the heating plants of dwelling houses andother buildings in conjunction with automatic control systems.

The basic object of the invention is the production of a burner of thistype incorporating a feature that functions under minimum fireconditions as a pilot burner for which reason it is so termed herein. Ina general way, the invention may be characterized as a burner within aburner.

More specifically stated, the primary purpose,

oi the invention is the production of a bowl type burner enclosing apilot burner that is similar in principle to a bowl type burner andwhich composite unit operates effectively, economically, with a cleanfire, and otherwise satisfactorily, throughout a wide range of firesfrom minimum or pilot fire to high fire on a grade of fuel customarilyemployed in burners of the type in question and known as fuel oil andwhich is desirably supplied from the same source throughout the entirerange of operation. The supply of combustion air automatically adjustsitself to the variable conditions encountered throughout said range,whereby the size of' the fire is governed entirely by the amount of fuelfed.

Other objects and advantages will appear as this description proceeds,among which are the provision of a relatively simple and inexpensiveconstruction, and one that facilitates lighting and cleaning and effectsready ignition of the fuel supply for higher fires from the flame of thepilot burner thus insuring smoothness of operation during the period oftransition from pilot to higher fire.

In the accompanying drawings that form a part hereof, Fig. l is acentral vertical section through a liquid fuel combustion apparatusembodying the invention; Fig. 2 is a similar section, as indicated bythe line 2-2 of Fig. 3, through the pilot burner and adjacent parts ofthe burner bowl on a scale considerably enlarged over that of Fig. 1;Fig. 3 is a plan view of the parts disclosed in Fig. 2; Figs. 4 and 5are views similar to Figs. 2 and 3, respectively, showing a modificationof the invention; and Fig. 6 is a schematic representation of theinvention including fuel feeding means and an automatic control system.

The burner bowl or pot of the combustion apparatus herein disclosed isdesignated generally by thereference numeral l and it comprises anannular top wall 2, a peripheral wall 3 and a bottom wall 4. The innerportion of the top wall is horizontal and at equally spaced partsthereabout the wall is formed with bays 5 for the purpose of increasingthe radial dimension of the horizontal portion at these points. Theperipheral wall 3 is provided with air inlet openings or perforations 6,three circumferential series of such perforations being shown.

Adjacent the front of the apparatus, the peripheral wall 3 has arelatively large lighting and clean-out opening ID that is surrounded bya forwardly projecting flange l I against the outer end of which isadapted to seat a gasket I 2 of suitable non-inflammable packingmaterial carried within the channeled edge portion of a member l3 thatis swiveled, through a pivotal element M, to the inner end of a plug l5.The enlarged outer end iii of this plug fits Within a sleeve ll thatsurrounds the flange 4| and is secured at its inner end to the burnerbowl or pot. The enlarged end 46 of the plug is notched at diametricallyopposite points for the passage of projections or rollers that extendinwardly from the sleeve ll, one of said notches being shown at H8 inFig. l, and the corresponding projection or roller at I9. The front edgeof the enlargement of the plug is: cut away on a taper to one side ofeach of the notches thereby to provide a cam portion 20 for cooperationwith the corresponding projection or roller, these parts cooperating topress the plug inwardly so as to'seal the joint between the gasket l2and the flange it when the plug is turned clockwise by means of itshandle M.

The bottom wall 4 of the burner bowl I is slightly dished, and at itscenter is provided with an opening in which is secured the lower end ofan air tube 25 that is surmounted by an air distributor designated,generally, by the numeral 26 and later to be described in detail. Weldedor otherwise secured to the exterior of the bottom wall 4 are insulatingshields 30 and 3|, having central openings that align with the air tube25,2. funnel 32 being shown as having itssmaller end welded within thecentral opening of the outer shield 30.

Liquid fuel is adapted to be delivered to the burner bowl or pot througha supply pipe 35 that passes through openings in the shields 30 and BIand in the wall 4, the pipe being Welded or otherwise secured to saidwall with a leak-proof joint. As disclosed in Fig. 6, the supply pipe 35is a part of the communicative connections between the burner and asource 36 of liquid fuel supply, such source being represented as atank. Liquid fuel gravitates from the tank through a pipe 3! to achamber 38 wherein a float controlled valve (not shown) establishes amaximum liquid level within the portion of the system including theburner bowl, sllCh level being designated by the dot-and-dash line a. inFig. 1. The fuel feedingand control means shown in Fig. 6 constitutesthe subject matter of an application bearing Serial No. 273,969, filedMay 16, 1939, by one of the present applicants, Theodore B. Focke.

Reference may details, although said means may be described briefly asincluding a by-pass valve 40, a metering valve 4 I, and a suitableautomatic control system for governing the flow of fuel within the rangebe made to said application for of operation between pilot and highfires. The

maximum flow is controlled by the metering valve 4|, which may bemanually adjusted through its stem 68. Also by means of this meteringvalve the flow may be entirely shut off during seasons in which it isdesired the combustion apparatus shall be inactive.

Disposed above and in spaced relation to the inner horizontal portion ofthe top wall 2 of the burner bowl is a ring-like member I whose inneredge is flanged upwardly at II. From its inner horizontal portionadjacent the flange II, the member 10 flares upwardly at a slight angleand ioins, through a vertical portion I2, a relatively wide horizontalperipheral flange I3. The member I0 is rigidly secured to the top wall 2by posts '5 which have their upper and lower ends enraged throughopenings in the member I0 and 20p wall 2 and desirably connected-to saidparts iy welding. The posts I5 are located at the radially enlargedparts of the inner horizontal.

portion of the top wall 2 provided by the previously mentioned bays 5.

An annular element 11, preferably of relatively thin sheet steel havingthe quality to effectively withstand the heat to which it is subjected,has its upper cylindrical end I8 fitted within the flanged edge 'II ofthe ring-like member 10 and secured thereto, as by welding. From itscylindrical end 18 the element converges downwardly in frusto-conicalform and therebelow assumes cylindrical shape to provide a shallowvertical wall 'that constitutes a neck 19, the element beyond such neckbeing flanged outwardly over the inner edge portion of the wall 2 towhich it is secured, as by welding. The neck 19 is provided with acircumferential series of relatively closely spaced perforations oropenings 80, while the frusto conical portion thereabove is providedwith an annular series of perforations or openings BI.

Surrounding the burner bowl I is an air compartment 85 enclosed by aperipheral wall 86, a

circular bottom wall 81 and an annular top wall 88. This latter wall hasits contracted upper end fitted over and secured, as by welding, to thevertical portion 12 of the ring-like member I0, and its flared lower endis surrounded by a vertical flange that fits within the upper edge ofthe peripheral wall 86 ,to which it is fastened by screws 89. The bottomwall 81, apertured to accommodate the supply pipe 35, is provided withan opening 90 surrounded by a depending flange to which may be connectedan air supply duct (not shown) that may lead from a suitable airimpelling means, such as a fan or blower. A combustion chamber 95 isenclosed by a drum 96 within the lower end of which is fitted an annularbottom wall 91 whose inner portion is interengaged with the ring-likemember I0 and is fastened to the peripheral flange 13 thereof by bolts98.

The operation of the apparatus, as thus far described, may be set out,briefly, as follows: Assuming that the burner is functioning at anystage above pilot fire, a rich mixture of primary air (entering throughthe perforations I5) and fuel vapors (generated by heat from the flameabove), rises through the throat I0 into the chamber 95 where, by thesecondary air admitted through the openings 8|, it is converted into ahighly combustible mixture and is a practically completely consumed. Tothe furtherance of this -end, additional secondary air is supplied tothe central portion of the column of rich mixture, as it ascends throughthe throat of the burner, by the previously mentioned air distributor25, the same having openings in its top and side walls, as willpresently appear.

The air distributor 26, shown in detail 2 and 3, 1s desirablyconstructed of sheet metal and comprises a circular top wall I05, aperipheral wall I06 and a bottom wall I0'I. The latter wall is formedwith an upwardly extending sleeve I00 that fits over the air tube 25,the bottom .wall resting upon a.shoulder I09 of said tube. Theperipheral wall I06 is cylindrical and receives, at its upper and lowerends, the flanged peripheral portions of the top wall I05 and bottomwall I0'I, respectively, the parts being welded or otherwise securedtogether. The peripheral wall I06 includes several-desirably four-inwarddepressions III] of such character as to provide radial walls III havingopenings II 2 through which air escapes from the interior of thedistributor in a direction tangent to the cylindrical wall I06. The topwall I05 has a circular series of apertures II5.

Surrounding the air distributor is a unit designated generally by thereference numeral I20, and shown as made up of two frusto-com'cal wallsections I2! and I22. The upper section I2I is of relatively slighttaper, and its lower end is fitted over a flange I23 that forms theupper terminal of the lower section I22, the latter section beingrelatively shallow and flaring downwardly at a considerably greaterangle than the former section to where it terminates in a substantiallyvertical flange I24. Constructed as described and provided withopenings. I25, the unit I 20 constitutes, in effect, an upstandingperforated wall that encloses what may be termed the pilot burner space.The unit I20 is held in proper or concentric relation to the airdistributor 26 by fingers I21 that extend radially inwardly from thesection I2I and engage the cylindrical wall I06 of the air distributor,such fingers being shown as woven asbestos fiber or the like, and anintermediate layer I3I of some such material as coarse wire mesh. Thefuel difiuser I30 is shown as circular and is preferably of a diametersomewhat greater than that of A relatively large notch I33, whose sidesare shown as at right angles to each other, is formed in the diffuserfor the obvious purpose of accommodating the supply pipe'35, as well asfor a further and important purpose which will presently be explained.

During low or pilot fire, when a very small quantity of fuel is beingfed, the fuel saturates the diffuser I30 within thebottom of the pilotburner space enclosed by the unit I20 and is vaporized by the heat givenoff by the surround ing parts of the burner and the flame that occupiessaid space. Under the conditions now prevailing, the pilot burner(comprised of the air in Figs.

the bottom of the unit I20.

distributor and the upstanding D forated wall or unit I20) functions inmuch the same way as the complete burner at higher fire. That portion ofthe interior of the burner bowl surrounding the pilot burner serves thelatter at low fire substantially as the air chamber serves the burnerbowl I at higher fire. Primary air is admitted to the pilot burner spacethrough the lower openings I25 producing, with the fuel vapors, amixture to which secondary air is added through the more elevatedopenings I25 and through the openings III of the air distributor 26.Practically completecombustion of the fuel at low tire is thus effected,wherefore the formation of carbon to any appreciable degree upon thepilot burner parts is avoided. a

When the automatic control system operates to increase the fuel supply,the fuel in excess of the amount fed for pilot fire purposes fiows tothe surrounding portion of the burner bowl; and as the fuel supply isthus increased and difius'ed, the flame of the pilot burner iscommunicated to the fuel inthe surrounding portion of theburner bowlthrough the notch I33 beneath the adjacent edge portion of the unit I20. This insures immediate ignition of the oil escaping to the suris tofacilitate this operation that the outer ends I20-of the members I20 areflared outwardly so rounding portion of the burner bowl so that there isno perceptible break in the'continuity of operation during thetransition from minimum or pilot fire to higher fire. Under theseconditions the difiuser I serves as a wick and aids in vaporizing thefuel flowing into the surrounding burner bowl.

In Figs. 4 and 5 are shown modifications of the air distributor and fueldiffuser, the former being designated, generally, by the referencenumeral 26, and the latter by the reference numeral I30. The bodyportion of the'present air distributor'is in the nature of an invertedcup comprising a circular top wall I and a cylindrical side wall I36;and the lower end of the peripheral wall fits over a substantiallyvertical flange I31 that surrounds the top of an invertedfrustoconicalwall I38 whose lower end is turned inwardly and welded or otherwisesecured to the corresponding end of a sleeve I39 that fits over theupper end of 'the air tube 25 and bears against the shoulder I09thereof. The top wall I35 is provided with a circular series of openingsI40, and the walls I36and I38 with openings HI and I42, respectively. Inthis case, the air is directed radially of the pilot burner space by theopenings I 4| and I42, while air escapes from the openings I40 in avertical direction.

The diffuser I30 is made up of layers of fibrous material separated byan intermediate layer I of wire mesh, as in the former case, but in thepresent modification notches I46 open through the edge of the diffuserand extend inwardly a substantial distance beyond the base flange of theunit I20. An opening I48, shown as triangular, accommodates the feedpipe I35.

The burner involving the air distributor 26 and diffuser I30 operatessubstantially like the one above described, with the exception that theair issuing from the distributor into the pilot burner space is notgiven a swirling action.

With respect to the diffuser I30, when the burner goes from minimum orpilot fire to higher fire, the flame of the pilot burner is communicatedto the fuel in the surrounding portion of the burner bowl through thenotches I46.

For the purpose of cleaning, inspection or replacement, the unit I20,the air distributor, and

that beneath any of them a be readily engaged.

Having thus described our invention, what we claim is:

1. A liquid fuel burner comprising a bowl having means for admitting airthereto in the region of its peripheral wall, an air distributorsituated substantially centrally of the bowl for supplying additionalair thereto, an upstanding perforated wall surrounding the airdistributor and spaced intermediate the same and the peripheral wall ofthe bowl, said upstanding wall enclosing a pilot fire space, and meansfor supplying liquid fuel to said space in limited quantity for pilotsuitable lifter may fire, and, in greater quantity, to the portion ofthe bowl outside said space for higher fire.

of its peripheral wall, an air distributor situated substantiallycentrally of the bowl for supplying additional air thereto, anupstanding perforated wall surrounding said distributor and spacedintermediate the same and the peripheral wall of the bowl, saidupstanding wall enclosing a pilot fire space and the distributor havingprovisions for expelling air into said space in such manner as to impartto the air a swirling action, and means for feeding liquid fuel to saidspace in limited quantity for pilot fire, and thence, in greaterquantity, to the portion of the bowl outside said space for higher fire.

3. A liquid fuel burner comprising a bowl provided with meansforadmitting air thereto in the region of its peripheral wall, anupstanding perforated wall enclosing a pilot fire space substantiallycentrally within the bowl, means for feeding liquid fuel to said spacein limited quantity for pilot fire and in greater quantity to theportion of the bowl outside said space for higher fire, and a fueldiffuser adjacent the bottom of said space and extending outwardlybeneath said upstanding wall to the surrounding portion of the bowl,said diffuser being shaped to provide a void beneath said upstandingwall thereby to facilitate ignition of the fuel outside said space fromthe pilot fire therein.

4. A liquid fuel burner comprising a bowl hav ing means for admittingair thereto in the region of its peripheral wall, an air tube risingcentrally of the bowl, an air distributor surmounting said tube, anupstanding perforated wall surrounding the distributor and beingremovable from the bowl, means spacing said upstanding wall from thedistributor, the upstanding wall enclosing a pilot fire space, a fueldiffuser adjacent the bottom of said space and extending at intervalsoutwardly beneath the upstanding wall, and means for feeding liquid fuelto said spacein limited quantity for pilot fire, and thence, in greaterquantity, to the portion of the bowl out side said space for higherfire.

5. A liquid fuel burner comprising a bowl having'means for admitting airthereto in the region of its peripheral wall, an air tube risingcentrally of the bowl, an air distributor surmounting said tube, anupstanding perforated wall surrounding the distributor and beingremovable from the the distributor, the upstanding wall enclosing apilot fire space, a fuel diffuser adjacent the botthe fuel difiuser maybe lifted from the bowl. It

tom of the bowl surrounding the air tube and extending outwardly beneaththe upstanding wall, the same having voids in the region of said wallthrough which the pilot fire space communicates with the surroundingportion of the bowl, and means for feeding liquid fuel to said space inlimited quantity for pilot fire, and thence, in greater quantity, to theportion of the bowl outside said space for higher fire.

' 6. A liquid fuel burner comprising a bowl having means for admittingair thereto including a substantially central air tube, a distributordetachably engaged over said tube, and a perforated wall surroundingsaid distributor and having means spacing it therefrom, said wall beingremovable from the bowl, and means for delivering liquid fuelexclusively to the space enclosed by said wall in varying quantities tosustain operf ation throughout the entire range of the burner from pilotto high fire.

'7. A liquid fuel burner comprising a bowl hav ing means for admittingair thereto including a substantially central air tube, an airdistributor detachably engaged 'over said tube, a perforated wallsurrounding said distributor and having means spacing it therefrom, afuel difiuser surrounding the air tube between the aforesaid wall andthe bottom of the bowl and being so shaped as to dispose its edgepartlyinside and partly outside of said wall, said diffuser and theaforesaid perforated wall being removable from the bowl, and means fordelivering liquid fuel to the space enclosed by said wall in varyingamounts to sustain operation throughout the entire range of the burnerfrom pilot to high fire.

8. In combination, liquid fuel combustion apparatus including acombustion chamber, an air compartment therebelow, and a burner bowlsituated in said compartment and communicating at its top with thecombustion chamber, the bowl having means for admitting air from saidcompartment, an air distributor situated substantially' centrally of thebowl for supplying air to the central region thereof, an upstandingperforated wall surrounding the distributor in-.

termediate the same and the peripheral wall' of the bowl and enclosing apilot fire space that is open at the top, liquid fuel supply means fordelivering fuel to the pilot fire space and to the space outwardly ofsaid upstanding wall, and a control system for varying the quantity offuel delivered by said means throughout the entire operating range ofthe apparatus from pilot to high fire.

9. A liquid fuel burner comprising a bowl having means for admitting airthereto in the region of its peripheral wall, an air distributorsituated centrally of the bowl, an upstanding perforated wallsurrounding the distributor and being removable from the bowl, membersattached to the outer side of said upstanding wall and having fingersprojecting through openings therein for spacing said wall from-thedistributor, the upstanding wall enclosing a pilot fire space, and

means for feeding liquid fuel to said space in" limited quantity forpilot fire, and thence, in greater quantity, to the portion of the bowloutside said space for higher fire.

10. A liquid fuel burnercomprising a bowl having means for admitting airthereto in the section and enclosing limited quantity for pilot fire,and, in greatera pilot fire space, and means for feeding liquid fuel tosaid space in quantity, to the portion of the space for higher fire.

,11. A liquid fuel burner comprising a combowl outside said bustionchamber, a burner bowl situated below said combustion chamber and havinga top wall provided with an opening through. which the bowl communicateswith said chamber, the peripheral wall of said bowl being provided withair openings, a perforated annular partition of less height than theperipheral wall dividing said therefrom may rise directly through theaforeregion of its peripheral wall, an air distributor bowl intoinnerand outer combustion compartments, means for admitting air to theinner compartment, and further means for feeding fuel to both of saidcompartments for high fire and, in smaller quantity, to the innercompartment only for lower fire.

12. A liquid fuel burner comprising a combustion chamber, a burner bowlsituated below said combustion chamber and having a top wall providedwith an opening through which the bowl communicates with said'chamber,the peripheral wall of said bowl being provided with air open-.

ings, an annular partition dividing said bowl into inner and outercompartments, the inner compartment being open at the top so thatproducts said opening into the combustion chamber, means for feedingfuel to both of said compartments for high fire andin smaller quantityto the inner compartment only for pilot fire, and a wick arranged so asto aid in vaporizing fuel flowing into the. outer compartment whenchanging from pilot fire to higher fire.

13. A liquid fuel burner comprising a combustion chamber, a burner bowlsituated below said combustion chamber and having a top wall pro-.

vided with an opening through which the bowl communicates with saidchamber, the peripheral wall of said bowl being provided with airopenings, an annular partition dividing said bowl into inner and outercompartments, the inner compartment being open at the top so thatproducts therefrom may rise directly through the aforesaid opening intothe combustion chamber, means for feeding fuel to, both of saidcompartments for high fire and, in smaller quantity, to the innercompartment only for pilot fire, and a wick lying on the bottom of thebowl below the annular partition and extending into both compartments.

14. A liquid fuel burner comprising a combustion chamber, a burner bowlsituated below said combustion chamber and having. a top wall providedwith an opening through which the bowl communicates with said chamber,the peripheral wall of said bowl being provided with air openings, anannular partition dividing said bowl into inner and outer compartments,the inner compartment being open at the top so that products therefrommay rise directly through the aforesaid opening into the combustionchamber, means for feeding fuel to both of said compartments for highfire and, in smaller quantity, to the inner compartment only for pilotfire, and a wick lying on the bottom of the bowl below the annularpartition and extending into both compartments, there being a passagewayleading from the inner to the outer compartment'adjacent said wick.

THEODORE B. FOCKE. JOSEPH R. KIRKPATRICK.

